An Etymological Dictionary of the German Language/traut
traut, adj., ‘beloved, dear,’ from the equiv. MidHG. and OHG. trût; allied MidHG. trût, m. and n., ‘sweetheart, spouse.’ Since there is no corresponding word in the Teut. dialects with a Goth. form of the dental, it cannot be decided whether traut must be connected with trauen; in any case, the form and meaning admit of our regarding it as the old to partic. (comp. laut, falt, zart) of the root trū̆, treu, seen in trauen and treu, so that its lit. meaning is ‘one in whom confidence or trust is reposed.’ The borrowed Romance words beginning with d (comp. Ital. drudo, m., ‘lover,’ druda, f., ‘mistress,’ drudo, ‘gallant, brave,’ Fr. dru) presuppose a Goth. *drûda-, which could not be from the same root as Goth. trauan, ‘to trust.’ The connection with Gael. drúth, ‘wanton, pert,’ W. drud, ‘bold,’ is obscure; it may be primit. allied (Aryan root dhrū̆).